JP2001106220A - Production method for pulp mold molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for a pulp molded body which does not require finishing process, etc., and with which the end of an opening part can be formed in a desired shape. SOLUTION: A wet molded body having an opening is formed by piling pulp fiber on the paper making face of a paper making form, and the wet molded body is dewatered and dried for producing a pulp mold molded body 7. After the top end of the opening of the wet molded body is pressed downward by a predetermined means for forming the pressed-in part thick, an expandable core 8 is placed in the inside of the wet body, and the core 8 is expanded for pressing the wet molded body including the pressed-in part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a pulp molded article having an opening, and more particularly to a method for producing a pulp molded article capable of molding an end face of the opening into a desired shape.

[0002]

2. Description of the Related Art As a method for finishing an end of an opening in a pulp molded article having an opening, the end is cut by a predetermined means to make a cut surface smooth. There is a way to do that. However, in this method, delamination is likely to occur in the molded article due to the cutting, and the strength of the molded article is reduced, and the sealing property when the opening is sealed with a cap or the like may be reduced. Moreover, there is a possibility that the appearance of the molded article may be deteriorated.

As another method, a method is known in which an edge or a flange extending laterally is formed at the end of the opening, and the peripheral edge of the ear (flange) is cut at a predetermined width. ing. But,
By forming the ears (flanges), the caps and the like also become larger by that amount, and the overall appearance is reduced.

Further, any of the above-mentioned methods requires a certain finishing step, which complicates the manufacturing process.

As a method for finishing the end of the opening, there is a technique described in Japanese Patent Application Laid-Open No. S51-35710. In this technique, the end of a molded product is pressed by an end molding material. Since the pressing of the inside of the molded product by the male mold is performed at the same time, the pushing amount by the end molding material is small,
In addition, since a flexible member is used for the end portion forming material, the dimensional accuracy and surface roughness of the end portion of the molded product are deteriorated, and there is a problem that the sealing property by a cover or the like covering the opening is insufficient. .
In addition, since the molded product is pressed by the male mold, there is a problem that it cannot be applied to a molded product having a hollow bottle shape or a vertical shape such as a side wall portion.

Accordingly, the present invention can form a molded article having excellent appearance, strength and sealing properties, and can form the end of the opening into a desired shape without the need for finishing. It is an object of the present invention to provide a method for producing a pulp molded article that can be manufactured. It is another object of the present invention to provide a method for producing a pulp molded article capable of forming an end of an opening into a desired shape even in a molded article having a hollow bottle shape or a vertical shape in a side wall portion.

[0007]

According to the present invention, a pulp fiber is deposited on a papermaking surface of a papermaking mold to form an undried molded article having an opening, and the undried molded article is dehydrated and dried. A method for manufacturing a molded article, comprising: pressing an upper end of the opening in the molded undried molded article downward by a predetermined means to increase the thickness of a pressed portion; The above object has been achieved by providing a method for producing a pulp molded article in which an expandable and contractible core is disposed, and then the core is expanded to press the undried molded article including the indented portion. is there. Also,
The present invention deposits pulp fibers on the papermaking surface of a papermaking mold,
A method for producing a pulp molded article by molding an undried molded article having an opening, and dehydrating and drying the undried molded article, wherein an upper end of the opening in the molded undried molded article is provided. Is bent downward by a predetermined means to increase the thickness of the bent portion, and an expandable and contractible core is arranged inside the undried molded body before or after the bending or simultaneously with the bending, and then the core is expanded to expand the core. The object has been attained by providing a method for producing a pulp molded article which presses the undried molded article including a bent portion.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. In the first embodiment, as a pulp mold molded body, a hollow molded body in the shape of a cylindrical bottle in which the diameter of the opening is smaller than the diameter of the body and the outer wall of the opening is formed with a threaded portion. Here is an example.

FIGS. 1 (a) to 1 (e) show a paper making process of a process for producing a pulp molded article. First, as shown in FIG. 1A, a pulp slurry is injected into a cavity 4 of a papermaking mold 1 in which a cavity 4 having a predetermined shape is formed by abutting a pair of split molds 2 and 3. The pouring may be performed under pressure of the pulp slurry. Each of the split dies 2 and 3 is provided with a plurality of communication holes 5 for communicating the outside with the cavity 4. On the inner surface of each split mold, a thread groove 6 is cut at a portion corresponding to the outer wall of the opening of the molded body to be molded. The inner surfaces of the split dies 2 and 3 may be covered with nets (not shown) each having a mesh of a predetermined size.

Next, split molds 2 and
3 is sucked from the outside to reduce the pressure inside the cavity 4,
The water in the slurry is sucked through the communication hole 5 and the pulp fibers are deposited on the inner surface (papermaking surface) of the cavity 4. As a result, on the inner surface of the cavity 4, a water-containing molded body 7 on which pulp fibers are deposited is formed.

When a predetermined amount of pulp slurry is injected,
The injection of the pulp slurry is stopped, and the inside of the cavity 4 is continuously sucked to further advance dehydration. After suction dehydration, Fig. 1
As shown in (b), the inside of the cavity 4 is sucked and decompressed, and the hollow core 8 which is expandable and contractible is removed.
Insert inside. In the present invention, the expansion and contraction means that the volume of the core 8 changes due to expansion and contraction, and that the core 8 itself does not expand and contract, but the fluid is supplied to or removed from the interior to reduce the volume. Is changed. Examples of the former include elastic materials such as urethane, fluorine-based rubber, silicone-based rubber and elastomer, and examples of the latter include plastic materials such as polyethylene and polypropylene used for bags and the like. In the present embodiment, the core 8 is made of an elastic material.

Next, as shown in FIG. 1C, a pressurized fluid is supplied into the core 8 to expand the core. The expanded core 8 presses the hydrated molded body 7 against the inner surface of the cavity 4. As a result, the inner surface shape of the cavity 4 is transferred to the molded body 7 and dehydration under pressure of the molded body 7 proceeds. As described above, since the molded body 7 is pressed against the inner surface of the cavity 4 from the inside of the cavity 4, the shape of the inner surface of the cavity 4 is accurately transferred to the molded body 7 even if the inner surface of the cavity 4 is complicated. Will be done. In addition, unlike the conventional manufacturing method, there is no need to use a bonding step, and thus the obtained molded body 7 has no joints and thick portions due to bonding. As a result, the strength of the obtained molded body 7 is increased and the appearance impression is improved. The pressurized fluid used to expand the core 8 is, for example, compressed air (heated air), oil (heated oil),
Other various liquids and gases are used. The pressure at which the pressurized fluid is supplied depends on the constituent material of the core 8, but is generally preferably 0.01 to 5 MPa, particularly preferably 0.1 to 3 MPa.

When the shape of the inner surface of the cavity 4 is sufficiently transferred to the molded body 7 and the molded body 7 can be dehydrated under pressure to a predetermined moisture content, as shown in FIG. The pressurized fluid is removed and the core 8 is contracted. Next, the contracted core 8
Is taken out of the cavity 4. Further, the papermaking mold 1 is opened, and an undried molded body 7 having a predetermined moisture content is taken out.

Undried molded product 7 taken out of papermaking mold 1
Is subjected to a heating and drying step shown in FIGS. First, as shown in FIG.
Is loaded into a heating mold 10 composed of a pair of split molds 12 and 13. The heating mold 10 is previously heated to a predetermined temperature. Further, the heating mold 10 is configured such that a cavity 14 having a shape corresponding to the outer shape of a molded body to be molded is formed by abutting the split molds 12 and 13. Also,
Each of the split dies 12 and 13 is provided with a plurality of communication holes 15 for communicating the outside with the cavity 14.
These structures are the same as the structure of the papermaking mold 1 used in the papermaking process shown in FIG.

After the loading is completed, as shown in FIG. 2 (b), the end surface finishing member 16 made of a metal cylindrical body or the like is lowered from above the opening 7a of the molded body 7 containing water. The lower end surface of the end surface finishing member 16 is smooth and flat.
A part of a core 18 having the same material and shape as the core 8 used for the pressure dehydration in the paper making process shown in FIG. 1 is fixed near the lower end of the inner wall of the end face finishing member 16. Under this state, the molded body 7 is formed by the end surface finishing member 16.
After the upper end of the opening 7a is pushed downward, the core 18 is inserted into the molded body 7. As a result, FIG.
As shown in the enlarged view of the encircled portion, the pushed-in portion rises and becomes thick.

Next, as shown in FIG. 2C, a pressurized fluid is supplied into the core 18, and through the core 18, the undried molded body 7 including the pushing portion is removed from the cavity 14 of the heating mold 10. To transfer the shape of the cavity 14. At the same time, as shown in an enlarged view of a portion surrounded by a circle in FIG.
Press from above and from the side by the core 18 to shape into the shape of the final product. In this state, the molded body 7 is dried by heating. As a result, the shape of the lower end surface of the end surface finishing member 16 is transferred to the upper end surface of the opening 7a of the molded body 7, and becomes smooth and flat.

After the heating and drying, the pressurized fluid in the core 18 is drained to reduce the core 18. Next, the end face finishing member 16
And the core 18 is taken out of the molded body 7. Further, the heating die 10 is opened and the dried molded body 7 is taken out.

According to the above embodiment, the end surface finishing member 1
By appropriately selecting the shape of the lower end face of 6, the shape of the end face of the opening 7a of the obtained molded body 7 can be controlled, and the sealing property with a cap or the like can be improved without special finishing. Can be improved. For example, the end face finishing member 16 may have a lower end shape as shown in FIGS. 3A and 3B. The molded body formed by using the end surface finishing member 16 having the lower end surface having such a shape has good sealing performance with a cap or the like in which the inner ring is formed.

Further, according to the above embodiment, after the pushing portion of the opening 7a is thickened, the thick portion is pressed by the core 18, so that the pushing amount can be increased and the molded body can be formed. Only the opening 7a can be made thick without making the whole thick, and the density can be increased. In addition, the operation of making the upper end part of the paper thick at the time of paper making is unnecessary, and the opening 7a can be made thicker by processing such as pushing or folding a paper made to a uniform thickness. As a result, the strength of the opening 7a, that is, the strength of the thread can be increased without changing the papermaking cycle, and the durability against opening and closing of the cap and the like and the sealing property with the cap and the like are improved.

Further, according to the above embodiment, the degree of pushing of the end face finishing member 16 and the degree of pushing by the core 18 are appropriately controlled, so that the opening 7
The thickness of a can be controlled. For example, the thickness of the opening 7a can be made larger than the thickness of other portions of the molded body 7, thereby improving the durability against opening and closing of the cap and the like and the sealing property with the cap and the like.

Next, a second embodiment and a third embodiment of the present invention will be described with reference to FIGS. The second
For the third embodiment, only the points different from the first embodiment described above will be described, and for the points not particularly described, the detailed description regarding the first embodiment will be applied as appropriate. 4 and 5, the same members as those in FIGS. 1 to 3 are denoted by the same reference numerals.

In the second embodiment, first, at the time of molding the undried molded body 7, a projecting portion extending horizontally inward of the molded body 7 is formed at the upper end of the opening 7a. For details,
As shown in FIG. 4 (a), a pulp slurry injection port 4a for communicating the cavity 4 in the papermaking mold with the outside of the papermaking mold is provided with:
The pulp slurry injection nozzle 9 is inserted. The pulp slurry injection nozzle 9 has a cylindrical shape, and a through-hole for injecting the pulp slurry is formed at the position of the central axis.

Next, the pulp slurry is injected into the cavity 4 through the pulp slurry injection nozzle 9, paper is made in the same manner as in the first embodiment, and the molded body 7 is formed on the inner surface of the cavity 4. This state corresponds to the state shown in FIG. 1A in the first embodiment. In this case, pulp fibers also accumulate on the lower surface of the pulp slurry injection nozzle 9, and an overhang 7 b extending horizontally inward of the molded body 7 is formed at the upper end of the opening 7 a.

After the formation of the molded body 7, the pulp slurry injection nozzle is removed from the papermaking mold, and the dewatering nozzle 11 to which the core 8 is fixed is fitted into the pulp slurry injection port 4a as shown in FIG. Insert core 8 into cavity 4
Insert inside. This state corresponds to the state shown in FIG. 1B in the first embodiment. Dehydration nozzle 11 is shown in FIG.
(A) has the same shape as the pulp slurry injection nozzle 9, and when the dewatering nozzle 11 is inserted into the pulp slurry injection port 4 a, the lower surface of the dewatering nozzle 11
The upper surface 7a is opposed to the overhang portion 7b formed at the upper end portion, and substantially abuts.

Next, FIG. 1 in the first embodiment
The same operation as the operation shown in (c) is performed, and the molded body 7 is dehydrated under pressure. In this case, since the core 8 also presses the overhanging portion 7b, the mechanical strength and shape retention of the overhanging portion 7b are improved. As a result, there is no possibility that the overhang portion 7b is deformed when the molded body 7 is removed from the papermaking mold and when the molded body 7 is loaded into the drying mold.

After the dehydration under pressure, the core 8 is taken out together with the dehydration nozzle 11, and then the papermaking mold is opened to take out a green body having a predetermined moisture content. The removed compact is then loaded into a heating mold heated to a predetermined temperature.

Next, as shown in FIG. 4 (c), a cylindrical projecting portion bending member 21 is inserted into the cavity 4, and the projecting portion bending member 21 moves the projecting portion 7b of the upper end 7a downward. Bend to make the bent part thick.
Since the core 18 is fixed to the projecting portion bending member 21, the core 18 is disposed in the molded body 7 together with the bending of the projecting portion 7 b by the projecting portion bending member 21. This state corresponds to the state shown in FIG. 2B in the first embodiment.

Subsequently, FIG. 2 in the first embodiment
By performing the same operations as those shown in (c) and (d), the molded body 7 is shaped into a final product and dried by heating.

In the third embodiment, as shown in FIG. 5A, the inside of each of the split dies 2 and 3 used for papermaking of the molded product is related to the flow of fluid, and the first manifold portions 2a and 2
3a and a second manifold section 2b, 3b, and the inner surface of the cavity 4 corresponding to each manifold section can be independently suctioned. The first manifold portions 2 a and 3 a are provided in the first region 2 on the inner surface of the cavity 4.
2a, while the second manifold portion 2b,
3 b communicates with the second region 22 b on the inner surface of the cavity 4.

At the time of molding the molded body, a pulp slurry injection nozzle 9 is inserted into a pulp slurry injection port as shown in FIG. Then, the pulp slurry is injected into the cavity 4 through the pulp slurry injection nozzle 9 and papermaking is performed in the same manner as in the first embodiment.
A molded body 7 is formed on the inner surface of the substrate. In this case, both the first manifold sections 2a and 3a and the second manifold sections 2b and 3b are open to the atmosphere or are in a suction state toward the outside of the mold. This state corresponds to the state shown in FIG. 1A in the first embodiment. In this case, pulp fibers also accumulate on the lower surface of the pulp slurry injection nozzle 9, and an overhang portion 7b slightly extending inward of the molded body 7 is formed at the upper end of the opening 7a. By forming the overhang portion 7b, the later-described bending can be easily performed.

After the formation of the molded body 7, the pulp slurry injection nozzle is removed from the papermaking mold, and in this state, the second manifold portions 2b and 3b are sucked toward the outside of the mold, and
The molded body 7 in the region 22b is subjected to suction dehydration. At the same time, pressurized air is pressed into the first manifold portions 2a, 3a from outside the mold, the first manifold portions 2a, 3a are opened to the atmosphere, or the first manifold portions 2a, 3a are closed, and the The space corresponding to the first region 22a, that is, the space near the upper end of the opening 7a in the molded body 7 and the space in the vicinity thereof is made negative pressure. Thereafter, as shown in FIG. 5 (b), when the pulp slurry injection port is sealed with the sealing plug 23, the pulp fibers deposited in the first region 22a are bent downward by the negative pressure, and the bent portion is bent. It becomes thick. As described above, at the time of this bending, if the overhang portion 7b is formed at the upper end, the bending can be easily performed.

Next, FIG. 1 in the first embodiment
The same operations as those shown in (b) to (d) are performed, and the molded body is dehydrated under pressure. Thereafter, the green body in an undried state is taken out of the papermaking mold and loaded in a heating mold. Heat drying of the molded body in the heating mold follows the first or second embodiment.
That is, in the case of following the first embodiment, FIG.
As shown in (d), the folded portion is slightly pushed in using the end surface finishing member 16, the upper surface of the folded portion is made smooth and flat, and the molded body is pressed by the core 18. In the case of the second embodiment, the overhanging bent member 21 shown in FIG. 4C is used, and the overhanging portion is positioned such that the lower end of the overhanging bending member 21 is located near the folded portion of the molded body. The bending member 21 is inserted into the cavity.
In any of the embodiments, the molded body is shaped into the shape of the final product by the core 18 and the molded body is heated and dried.

As an alternative to the third embodiment, a papermaking mold comprising split molds 2 and 3 shown in FIG. 6 can be used. FIG.
Indicates a state corresponding to FIG. The difference between the papermaking mold shown in FIG. 6 and the papermaking molds shown in FIGS. 5 (a) and (b) is that the third manifold part 2c, between the first manifold parts 2a, 3a and the second manifold parts 2b, 3b. 3c
Is formed. The third manifold section 2c,
3c communicates with a third region 22c on the inner surface of the cavity 4 between the first region 22a and the second region 22b. Then, when bending the molded body 7,
The state in which the negative pressure in the space in the molded body 7 corresponding to the third region 22c is higher than the space in the molded body 7 corresponding to the first region 22a. As a result, the pulp fibers accumulated in the first region 22a are reliably bent downward with the portion corresponding to the third region in the molded body 7 as a fulcrum.

According to the third embodiment (the embodiment shown in FIGS. 5A and 5B and FIG. 6), the first region 22a
Is folded so as to overlap the inner wall of the opening in the finally obtained molded article. Therefore, it is possible to increase the thickness of only the opening without increasing the thickness of the entire molded body. Since the thread is formed on the outer wall of the opening, the thickness of the opening is increased according to the present embodiment, so that the strength of the thread is improved and the sealing performance with the cap or the like is improved. .

The present invention is not limited to the above embodiment. For example, in FIG. 2, the core 18 need not be fixed to the end surface finishing member 16. Further, the material and shape of the core 18 may be different from those of the core 8 used for the pressure dehydration.

Similarly, in FIGS. 4B and 4C, the core 8 does not have to be fixed to the dehydrating nozzle 11, and the core 1
8 does not have to be fixed to the overhang portion bending member 21.

In the third embodiment, the overhang 7b may not be formed if necessary.

In the above embodiment, two split dies as a papermaking die and a heating die are used as one set. However, three or more split dies are used depending on the shape of the molded body 7 to be molded. They may be used as a set. Further, although a papermaking mold and a heating mold each composed of a set of split molds are used, a papermaking mold and a heating mold each composed of a male mold and a female mold may be used instead.

In the above embodiment, the papermaking step and the heating and drying step are performed using separate molds. Alternatively, the undried molded body is formed by heating the papermaking mold after papermaking. It may be dried by heating without removing it from the molding. The above embodiment is an example of a method of manufacturing a bottle-shaped container. Alternatively, a box-shaped carton-shaped container and containers of other shapes can be manufactured.

The production method of the present invention can be applied not only to a method of producing a pulp mold container used for storing contents, but also to a method of producing an object such as an ornament.

[0041]

According to the method for producing a pulp molded article of the present invention, a molded article excellent in appearance, strength, and sealability can be obtained without requiring special finishing. The part can be formed into a desired shape. Therefore,
The number of manufacturing steps can be reduced, and manufacturing costs can be reduced. In particular, it is suitable for molding a molded article having a hollow bottle shape or a vertical shape in a side wall portion. Further, according to the method for producing a pulp molded article of the present invention, the density and strength of the opening can be increased, and the durability against opening and closing of the cap can be improved. Furthermore, according to the method for manufacturing a pulp molded article of the present invention, the thickness of the opening can be increased, and thereby the durability against opening and closing of the cap can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a paper making process according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a heating and drying step in the first embodiment of the present invention.

FIG. 3 is a schematic view showing another form of the end face finishing member used in the first embodiment of the present invention.

FIG. 4 is a schematic view showing each step in a second embodiment of the present invention. FIG. 4 (a) corresponds to FIG. 1 (a), and FIG.
(B) corresponds to FIG. 1 (b), and FIG. 4 (c) corresponds to FIG.
Is equivalent to

FIGS. 5A and 5B are schematic diagrams showing each step in the third embodiment of the present invention, wherein FIG. 5A shows a paper making step, and FIG. 5B shows a suction dewatering step.

FIG. 6 is a schematic diagram (corresponding to FIG. 5 (b)) showing another method according to the third embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 papermaking mold 2, 30 split mold 2a, 3a first manifold section 2b, 3b second manifold section 2c, 3c third manifold section 4 cavity 7 pulp molded product 7a opening 7b overhang 8 core 9 pulp slurry injection nozzle DESCRIPTION OF SYMBOLS 10 Heating mold 11 Dehydration nozzle 12, 13 Split mold 14 Cavity 16 End surface finishing member 18 Core 21 Overhanging bent member 22a 1st area 22b 2nd area

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nonomura 2606 Kabane-cho Akabane, Haga-gun, Tochigi Prefecture Inside Kao Co., Ltd. 72) Inventor Hiroaki Kobayashi 2606 Akabane, Kaga-cho, Haga-gun, Tochigi Prefecture F-term in the Kao Corporation Research Laboratory (reference) 3E033 AA01 BA10 BA13 BB02 BB08 DA03 DB01 DD01 FA04 FA10 4L055 AF08 BF07 BF08 FA30 GA50

Claims (7)

[Claims] 1. A method for producing a pulp molded article by depositing pulp fibers on a papermaking surface of a papermaking mold, forming an undried molded article having openings, and dehydrating and drying the undried molded article. Then, after the upper end of the opening in the formed undried molded body is pushed downward by a predetermined means to make the pushed-in portion thick, a scalable core is disposed inside the undried molded body. And then expanding the core to press the undried molded body including the pushed-in portion. 2. A method for producing a pulp molded article by depositing pulp fibers on the papermaking surface of a papermaking mold to form an undried molded article having openings, and dehydrating and drying the undried molded article. The upper end of the opening in the formed undried molded body is bent downward by a predetermined means to make the bent portion thick, and before and after the bending or simultaneously with the bending, the inside of the undried molded body is formed. A method for producing a pulp molded article, comprising disposing an expandable and contractible core, and then expanding the core to press the undried molded body including the bent portion. 3. The papermaking mold comprises a set of split dies in which a cavity having a predetermined shape is formed, and a pulp slurry is injected into the cavity, and water in the pulp slurry is suctioned and dehydrated. The method for producing a pulp molded article according to claim 1 or 2, wherein the undried molded article is formed on an inner surface of the cavity. 4. After removing the undried molded body from the papermaking mold and loading it in a heating mold heated to a predetermined temperature, the end face finishing member is lowered from above the opening in the undried molded body. The upper end portion is pushed downward to make the pushed-in portion thicker, and then, while the core is expanded and the undried molded body is pressed, the undried molded body is heated and dried. 4. The method for producing a pulp molded article according to 3. 5. An overhanging portion extending horizontally inward of the molded body is formed at an upper end of the opening at the time of molding the wet molded body, After being taken out of the mold and loaded into a heating mold heated to a predetermined temperature, a projecting portion bending member is inserted into the undried molded body, and the projecting portion is bent downward by the projecting portion bending member, and 3. The undried molded body is pressed and the undried molded body is heated and dried in this state by making the bent portion thick, disposing and expanding the core in the undried molded body, and pressing the undried molded body. Or the method for producing a pulp molded article according to 3. 6. When dehydrating the formed undried molded body in the papermaking mold, a portion of the undried molded body other than the upper end portion of the opening is suction-dehydrated, and the inside of the undried molded body is dehydrated. The upper end of the opening and the space in the vicinity thereof are negatively pressured and the upper end is bent downward,
The method for producing a pulp molded article according to claim 2 or 3, wherein the bent portion is made thick. 7. A hollow pulp molded article having an opening, produced by the production method according to claim 1 or 2, wherein a screw portion is formed on an outer wall of the opening. A pulp molded article in which the thickness of the opening in the body is greater than the thickness of a portion other than the opening in the molded article.